feat(obs): 去掉宿主机网卡趋势，磁盘读写改按速率展示

Agent 不再采集网卡累计字节，看板与节点网络图仅保留访问日志已提供/接收。
磁盘 IO 按小时换算为 B/s 曲线，摘要为近 24 小时平均速率，并同步 Swagger。

frontend/lib/services/openflare/dashboard.service.ts

@@ -128,11 +128,9 @@ function normalizeNetworkTrendPoints(
     isCompactNetworkTrendPoint(item)
       ? {
           bucket_started_at: String(item[0] ?? ''),
-          network_rx_bytes: Number(item[1] ?? 0),
-          network_tx_bytes: Number(item[2] ?? 0),
-          bytes_received: Number(item[3] ?? 0),
-          bytes_provided: Number(item[4] ?? 0),
-          reported_nodes: Number(item[5] ?? 0),
+          bytes_received: Number(item[1] ?? 0),
+          bytes_provided: Number(item[2] ?? 0),
+          reported_nodes: Number(item[3] ?? 0),
         }
       : {
           ...item,

frontend/lib/services/openflare/types.ts

@@ -120,8 +120,6 @@ export interface NodeMetricSnapshot {
   storage_total_bytes: number;
   disk_read_bytes: number;
   disk_write_bytes: number;
-  network_rx_bytes: number;
-  network_tx_bytes: number;
   openresty_connections: number;
 }
 
@@ -924,8 +922,6 @@ export interface CapacityTrendPoint {
 
 export interface NetworkTrendPoint {
   bucket_started_at: string;
-  network_rx_bytes: number;
-  network_tx_bytes: number;
   /** L1 接收数据 sum(request_length) */
   bytes_received: number;
   /** L1 已提供数据 sum(bytes_sent) */
@@ -985,14 +981,8 @@ export interface DashboardOverview {
 
 export type CompactTrafficTrendPoint = [string, number, number, number];
 export type CompactCapacityTrendPoint = [string, number, number, number];
-export type CompactNetworkTrendPoint = [
-  string,
-  number,
-  number,
-  number,
-  number,
-  number,
-];
+/** [bucket, bytes_received, bytes_provided, reported_nodes] */
+export type CompactNetworkTrendPoint = [string, number, number, number];
 export type CompactDiskIOTrendPoint = [string, number, number, number];
 export type CompactDashboardNodeHealth = [
   number,